nvidea gforce2 card for my h.p. 7850

I got a gforce2 card for my h.p. 7850 there is an extra pci slot but there are no jumpers to disable the mother board video driver . I called h.p. tech support but they dont know what I should do. The tech said maybe I should`nt even try to install it. Has anyone dealt with this before? I need some help.